Disappearing act

Today we had help in our beachcombing. A neighbour kid was waiting at the top of the steps to the beach; were we going down? he asked. He isn't allowed to go alone. Yes, we were, so he raced down the steps and waited for us on the rocks below, then acted as our guide, running a few steps ahead always, shouting when he found another sun star, another fish, another big crab ...

He has sharp eyes. He found this long-armed brittle star for us:

Amphiodia, Long-armed Brittle Star

The central disc here is less than 1 cm across. The arms never stopped moving; it's hard to know how long they were.

We found a few more, some very tiny, under rocks at the low tide line. I picked one up and moved it to a sandy spot for a photo shoot. Watch what he does:

Stretched out on the sand, but already digging in.

5 seconds later.

10 more seconds. Almost hidden.

I caught him, before he disappeared completely...

And put him on a rock where he couldn't burrow.

When we had finished taking his picture, we replaced him on the sand and lowered his rock over him, very gently.